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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at */
#ifndef mozilla_KeyframeUtils_h
#define mozilla_KeyframeUtils_h
#include "mozilla/KeyframeEffectParams.h" // For CompositeOperation
#include "nsCSSPropertyID.h"
#include "nsTArrayForwardDeclare.h" // For nsTArray
#include "js/RootingAPI.h" // For JS::Handle
struct JSContext;
class JSObject;
namespace mozilla {
struct AnimatedPropertyID;
struct AnimationProperty;
class ComputedStyle;
enum class PseudoStyleType : uint8_t;
class ErrorResult;
struct Keyframe;
struct PropertyStyleAnimationValuePair;
namespace dom {
class Document;
class Element;
} // namespace dom
} // namespace mozilla
namespace mozilla {
// Represents the set of property-value pairs on a Keyframe converted to
// computed values.
using ComputedKeyframeValues = nsTArray<PropertyStyleAnimationValuePair>;
* Utility methods for processing keyframes.
class KeyframeUtils {
* Converts a JS value representing a property-indexed keyframe or a sequence
* of keyframes to an array of Keyframe objects.
* @param aCx The JSContext that corresponds to |aFrames|.
* @param aDocument The document to use when parsing CSS properties.
* @param aFrames The JS value, provided as an optional IDL |object?| value,
* that is the keyframe list specification.
* @param aContext Information about who is trying to get keyframes from the
* object, for use in error reporting. This must be be a non-null
* pointer representing a null-terminated ASCII string.
* @param aRv (out) Out-param to hold any error returned by this function.
* Must be initially empty.
* @return The set of processed keyframes. If an error occurs, aRv will be
* filled-in with the appropriate error code and an empty array will be
* returned.
static nsTArray<Keyframe> GetKeyframesFromObject(
JSContext* aCx, dom::Document* aDocument, JS::Handle<JSObject*> aFrames,
const char* aContext, ErrorResult& aRv);
* Calculate the computed offset of keyframes by evenly distributing keyframes
* with a missing offset.
* @see
* @param aKeyframes The set of keyframes to adjust.
static void DistributeKeyframes(nsTArray<Keyframe>& aKeyframes);
* Converts an array of Keyframe objects into an array of AnimationProperty
* objects. This involves creating an array of computed values for each
* longhand property and determining the offset and timing function to use
* for each value.
* @param aKeyframes The input keyframes.
* @param aElement The context element.
* @param aStyle The computed style values.
* @param aEffectComposite The composite operation specified on the effect.
* For any keyframes in |aKeyframes| that do not specify a composite
* operation, this value will be used.
* @return The set of animation properties. If an error occurs, the returned
* array will be empty.
static nsTArray<AnimationProperty> GetAnimationPropertiesFromKeyframes(
const nsTArray<Keyframe>& aKeyframes, dom::Element* aElement,
PseudoStyleType aPseudoType, const ComputedStyle* aStyle,
dom::CompositeOperation aEffectComposite);
* Check if the property or, for shorthands, one or more of
* its subproperties, is animatable.
* @param aProperty The property to check.
* @param aBackend The style backend, Servo or Gecko, that should determine
* if the property is animatable or not.
* @return true if |aProperty| is animatable.
static bool IsAnimatableProperty(const AnimatedPropertyID& aProperty);
} // namespace mozilla
#endif // mozilla_KeyframeUtils_h